Producing alkali-metal nitrate



Patented Jan. 22, i929.

STATES PATENT OFFICE.

WILHELM WILD AND CHRISTOPH BECK, F LUDWIGSHAFEN-ON-THE-RHINE, GER- MANY, ASSIGNORS TO I. G. FAR-BENINDUSTRIE AKTIENGESELLSCHAIT, 0F FRANZ FOBT-ON-THE-MAIN, GERMANY, A CORPORATION OF GERMANY.

ZEROJjUCING ALKALI-METAL NITRATE.

1% Drawin Application filed May 12, 1927, Serial No. 190,962, and in Germany July 8, 1926.

We have found that alkali metal chlorids can be converted into alkali metal nitrates by means of nitrogen oxids in admixture with oxygen or air in a highly advantageous man- 5 ner by causing the said gases to react with a solution of the chlorids of such concentration that the resulting nitrate is deposited in the solid state, either at once, or on cooling,'the reactions being carried out under increased pressure.- It has been found that the dimensions of the reaction chamber, and therefore the prime cost of the plant, are reduced, by a multiple of the pressure employed, as compared with the process carried out at atmospheric pressure. For example, increasing the pressure to 6 atmospheres, enables the size of the reaction'chamber to be'reduced to 1 per cent of the space required for operating at atmospheric pressure.

ried out may have any desired height; for example it may be 2, fr, 10, 50 or even more atmospheres. v Q The following example will further illustrate how our invention may be carried out in practice, but the invention is not restricted thereto. y

' Emample.

A solution containing alkali metal ions,

hydrogen ions, nitrate ions and chlorine ions saturated with alkali metal chlorid at room temperature is treated, in apressure resistant apparatus under a pressure of about 6 atmospheres, with a gas mixture consistin for example of 9 per cent of nitrogen oxi 15 per The pressure at which the process is carcent of oxygen and 76 per cent of nitrogen,

while or after warming the solution to about 35 C. After the nitrogen oxid is oxidized and absorbed by the solution in the form of 40 nitric acid, the pressure is released and solid alkali metal chlorid added to the solution at 35 C; The solution is then cooled to 15 C. whereby alkali metal nitrate is separated. In this way it is possible to produce in a given apparatus 100 times the quantity of alkali metal nitrate obtainable when working under atmospheric pressure.

We claim:

1. The process of producing alkali metal nitrate which consists in treating an alkali metal chlorid solution with a mixture containing nitrogen oxide and oxygen, under a pressure higher than atmospheric pressure, releasing the pressure after the oxidized nitrogen oxids are absorbed and adding so much of alkali metal chlorid that the alkali metal nitrate formed is deposited without evaporation of the solution.

2. The process of producing alkali metal nitrate which consists in treating an alkali metal chlorid solution with a mixture containing nitrogen oxide and oxygen under a pressure of six atmospheres while slightlywarming, releasing the pressure after the oxidized nitrogen oxids are absorbed and adding so much of alkali-metal chlorid that the alkali metal nitrate formed is deposited In testimony whereof we have hereunto set our hands.

WILHELM WILD.

CHRISTOPH BECK. 

